In the following discussion, reference to combustion devices that are part of a gas turbine is made; it will, however, be clear to those skilled in the art that the method can also be implemented in combustion devices for different applications.
A gas turbine can include a compressor, a combustion device and a turbine.
Combustion devices are known to include a body with:                a fuel supply for either a liquid fuel (for example, oil) or a gaseous fuel (for example, natural gas), and        an oxidiser supply (for example, air).        
During operation, the fuel and the oxidiser react within the combustion device and generate high pressure and temperature flue gases that are expanded in the turbine.
During transient operation, such as for example when the gas turbine is started up, switched off, during fuel switch over or also during other transient operations, problems can occur.
In fact, during these transient operations fluctuating pressure can generate within the combustion device; this fluctuating pressure can adversely influence fuel injection.
FIG. 1 shows an effect of the fluctuating pressure within the combustion device on the fuel injection. This FIG. 1 shows an example in which the fuel mass flow is reduced; this could be an example of a switch off. However, the same or similar conditions would also be present at the beginning of a start up or at the beginning and end of a switch over, and in general, each time the fuel mass flow supplied decreases and falls below a given mass flow.
FIG. 1 shows the fuel mass flow M injected through an injector as a function of time t. From FIG. 1 at least the following phases can be recognised:                before t=t1: steady operation with substantially constant fuel mass flow through the injector (curve 1);        between t=t1 and t=t2 (the fuel mass flow stays above a designated (e.g., critical) fuel amount Mc): the amount of fuel injected decreases, but the fluctuating pressure within the combustion device does not perceptibly affect fuel injection (curve 2);after t=t2 (e.g., when the fuel mass flow falls below a critical fuel amount Mc): in these conditions, since the amount of fuel is low, the fluctuating pressure within the combustion device alternatively promotes and hinders fuel injection, causing a fluctuating fuel injection. For example, curve 2 shows a theoretical run of the reducing fuel mass flow, and curve 3 an example of a possible real run of the reducing fuel mass flow.        
Fluctuating fuel supply into the combustion device generates large combustion pulsations.
Combustion pulsations largely mechanically and thermally can stress the combustion device and the turbine downstream of it, and therefore would desirably be counteracted.